Measuring instrument



Oct. 15, 1940. J. E. CAMPEN NG INSTRUMENT MEASURI Filed April 6, 1938 m "m Fain.

INVENTOR Josnun E CnMPm ATTORNEY Patented Oct. 1 5, 1940 2,217,859

iTE STAES MEASURING INSTRUMENT Joshua Earle Gampen, Prospect Park, Pa.

Application April 6, 1938, Serial No. 200,395

8 Claims. (Cl. 33-:167)

My invention relates to measuring devices and the line V-V of Fig. 1, looking in thedirection of more particularly to inside micrometers or calithe arrows;

NT OFICE pers, and has for an object the provision of a Fig. 6 is a view similar to that of Fig. 4 showing device of this type which is capable of measurthe attachment applied, by means of an adapter,

5 ing dimensions under conditions rendering the to a larger micrometer than that of Fig. 4; 5 use of previously known devices unsatisfactory. Fig.7 is an elevational view showing an inside A further object of my invention is the provimicrometer embodying my invention being insion of an inside micrometer whose overall length serted, while partially collapsed, into an intercan be reduced to materially less than its mininally, circumferentially grooved turbine cylinder;

mum measuring limit. Fig. 8 is a plan view of the lower half of the Another object of my invention is the proturbine cylinder of Fig. 7, showing the micromvision of a straight inside micrometer whose no-reter straightened preparatory to measuring the mal overall length can be reduced an amount diameter of the groove in whichit is received;

greater than its measuring range in a single and,

simple movement. Fig. 9 is an elevational view showing a modi- 5 Another object is the provision of a rod-like fication of my invention. inside micrometer having a pivot joint inter- In the drawing there is shown a straight in mediate its ends. side micrometer ill of a construction well known Yet another object is the provision of an atin the art. An extension attachment 26 is tachment for standard straight inside micromclamped to the micrometer near one end thereof 20 eters now on the market which will adapt them, and includes a pivotal joint, as at 47, which for use in otherwise inaccessible places. allows an outer portion 43 to be swung between A further object of my invention is the proa position in longitudinal alignment with the vision of a pivoted extension attachment for micrometer and a position at an angle thereto,

standard straight inside micrometers in which whereby the overall length of the combined mi- 25 the extension can be swung into alignment with crometer and attachment may be changed matethe micrometer after the device has been placed rially by a single simple pivotal movement. in the desired position. Referring now to Fig. 1, there is shown a Another object of my invention is the provision straight inside micrometer I0, constructed and of a device capable of measuring the inside dioperating in a manner well known to those 30 ameters of grooves in the wall of a cylindrical skilled in the art, and comprised by a shank H bore, which grooves are deeper than the measurprovided at orie end with' a chuck I2 in which is ing range of the device. held a removable anvil l3 having a knurled A further object of my invention is the provifinger piece I i. At the opposite end of the mision of an extension attachment for standard crometer there is a fixed anvil i6 and adjacent 35 straight inside micrometers, together with an thereto is rotatably mounted a cylindrical sleeve adapter, whereby one size of attachment may fit I! having a knurled surface [8 for contact by micrometers of different sizes. the fingers of the operator. The inner end of the These and other objects are effected .by my sleeve H is beveled, as at I9, the beveled surface invention as will be apparent from the following having a circumferential series of graduations 20 40 description and claims taken in accordance with thereon. A hub portion 2|, adjacent the inner the accompanying drawing, forming a part of end of the sleeve H, has a longitudinal series this application, in which: of graduations 22 thereon cooperating with the Fig. l is a side elevational view of my extengraduations 20 to indicate dimensions measured sion attachment applied to a well known type of by the micrometer. 45 inside micrometer; The numeral 26 indicates, in its entirety, an Fig. 2 is a plan view of the structure of Fig. 1, extension attachment comprised by a body 21 a portion of the micrometer being omitted; having an upper plate 28 and a lower plate 29 Fig. 3 is a View similar to that of Fig. 2, with connected in spaced parallel relation by a side the extension disposed at a 30 degree angle to wall 3|, whereby a rectangular space 32 is pro- 50 the longitudinal axis of the micrometer; vided between the plates 28 and.29.

Fig. 4 is a longitudinal sectional View taken on The body 2'! is removably attached to the mithe line IV-IV of Fig. 2, looking in the direction crometer sleeve I! by a split ring 33 embracing of the arrows; the knurled portion N of the sleeve. The ring Fig. 5 is a transverse sectional viewtaken on 33 is provided with parallel projecting ears 34 55 adjacent the split and may be tightened to securely grip the sleeve l l by adjustment of a screw 36 whose shank extends freely through one of the ears 3d and is threadedly received in the other ear, in a well known manner.

A flat arm 3! is provided. with a depending neck 38 carrying a split ring 39 provided with parallel ears ll having an adjustment screw 42, all functioning in a manner similar to the split ring 33, ears 34 and screw 36 described above. Clamped within the split ring 39 is an extension standard 33 having anvil portions 4t and 46 at its outer and inner ends, respectively. The flat arm 31 is of such a thickness as to be closely yet movably received. in the space 32 between the plates 28 and 29. A cylindrical pin 41 extends vertically through the upper plate 28, through the arm 3'! and into the lower plate 29 to secure the arm 3'11 to the body 2'! for pivotal movement 'of the former relative to the latter. Such movement of the arm is limited in one direction by the side wall 3!, against which the edge of the arm may abut. When the arm is in abutting relation with the side wall 3i (Figs. 1 and 2) the extension standard 33 is longitudinally aligned with the micrometer, with the inner anvil 46 of the extension standard contacting the micrometer anvil it.

Means is provided for holding the arm in contact with the side wall 3! during normal use of the device and is comprised by a set screw 48 threadedly received in a vertical hole 29 in the plate 28. Preferably, the set screw is provided with a knurled head 5!. As shown in Fig. 5, the point of the set screw enters a depression 52 in the upper surface of the arm 37 to positively lock the arm in its operative position. Preferably, the depression 52 is offset away from the side wall 3! relative to the centerline of the set screw, so that tightening of the screw tends to force or wedge the arm against the side wall.

Preferably also, the pivot pin M is slightly olfcenter toward the side wall 3 ll relative to the longitudinal centerline of the assembled micrometer and attachment, to provide for quick reduction of the overall length of the micrometer and attachment, and for producing snap action engagement of anvils 36 and 36 upon pivoting of the arm and extension standard to operative position in longitudinal alignment with the micrometer.

The micrometer iii, without the attachment 26, can be used for measuring only within certain definite limits, determined by the design and dimensions of the device. For example, by substituting for the anvil i3, anvils of greater length, the micrometer it might serve for measurements varying from 10 to 20 inches. With the use of my attachment 26, extensions of greater length may also be substituted for the extension standard 43, with the result that the measuring limits of the combined structure might be from 10 to 30 inches. In order to measure dimensions above this range a larger micrometer would have to be used.

In Fig. 6 I have shown means whereby the same extension attachment 25, shown in the preceding figures as fitting the micro-meter 10, may be used with a larger micrometer it). In this figure the same attachment 25 is secured to a relatively large micrometer 10 by use of an adapter 55 having a split sleeve 51 clamped about the knurled portion I8 of the micrometer sleeve H by a pair of parallel projecting ears 58 drawn toward each other by a screw 59 in a well known manner. The split sleeve 51 has extending therefrom, in alignment with the longitudinal axis of the micrometer, a cylindrical shank 6| of such a diameter that it may be closely received within the split ring 33 of the attachment 26. The shank 6! is internally recessed for a portion of its length, as at 62, for reception of the anvil I6 of the micrometer. An anvil-63 extends from that end of the shank 8i opposed to the split ring 51 and bore 62. The dimension A, from the inner end of the recess or bore 62 to the tip of the anvil 63, preferably is exactly one inch or a multiple thereof in order that with a zero reading of the micrometer calibrations the overall length of the combined micrometer, adapter, and extension attachment will be an exact multiple of an inch.

In Figs. 7 and 8 I have illustrated one situation in which my invention may be used to great advantage. A turbine cylinder 65 is formed by an upper casing 61 and a lower casing 68 provided with meeting flanges 69 and Hi, respectively. The casings El and 68 are joined by means such as bolts H extending through the flanges 69 and Ill. The cylinder 65 is provided with a longitudinally tapered bore 72 and a plurality of circumferential grooves 73, for the reception of the root portions of stationary blades or vanes (not shown). These grooves must be machined to prescribed depths or diameters which must be checked by micrometer readings. As these grooves usually have a depth of considerably more than oneinch, it is impossible to get a standard straight micrometer into opposed grooves, the limit of adjustment of such a micrometer being only one inch.

Fig. '7 shows a combined micrometer and attachment in position to be inserted into a groove. The arm 37 of the attachment has been swung out of longitudinal alignment with the micrometer to greatly reduce the overall length of the device.

Fig. 8 shows the arm 37 and extension standard 13 swung to operative position in longitudin a1 alignment with the micrometer, for determination of the diameter of the groove "i3 by relative rotation of the sleeve ill and shank it. After taking of the reading, the device may be shortened, for removal from the groove, by a single swinging movement of the arm 37.

In Fig. 9 I have shown another adaptation of my invention. In this construction a standard straight inside micrometer T l, similar to the micrometer W of Fig. 1, is provided with a pivoted joint FE intermediate the ends of the shank portion 15. The joint is comprised by a bifurcated portion ill and a fiat portion '58 swingably mounted in the space between the legs of the bifurcated portion. A pivot pin 79 extends through the bifurcated portion I? and the frat portion '18 to forms, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. An attachment for inside calipers comprising a body portion, means for securing said portion to an inside caliper adjacent an end thereof, a holding member carried by the body portion, and an extension member held thereby normally longitudinally aligned with the caliper, said holding member being movable relative to the body portion whereby the extension member may be disposed at an angle to the longitudinal axis of the caliper.

2. An attachment for inside calipers comprising a body portion, means for securing said portion to a straight inside caliper adjacent an end thereof, an arm carried by said portion and provided with holding means, and an extension standard held thereby normally longitudinally aligned with the caliper, said arm being movable relative to the body portion whereby the extension standard may be disposed at a material angle to the longitudinal axis of the caliper to reduce the overall length of the combined caliper and attachment.

3. An attachment for inside calipers comprising a bifurcated body portion, a first split ring clamp carried by the body portion for attaching the latter to an inside caliper, an arm having one end mounted in the bifurcation of the body member for pivotal movement about an axis at right angles to the longitudinal axis of the split ring clamp, a second split ring clamp carried by the other endof the arm normally in longitudinal alignment with the first split ring clamp, and an extension standard held by the second split ring clamp.

4. An attachment for inside calipers comprising a bifurcated body portion, a first split ring clamp carried by the body portion for attachin the latter to an inside caliper, an arm having one end mounted in the bifurcation of the body member for pivotal movement about an axis at right angles to the longitudinal axis of the split ring clamp, a second split ring clamp carried by the other end of the arm normally in longitudinal alignment with the first split ring clamp, and an extension standard held by the second split ring clamp, the arm being swingable from a measuring position with the extension standard aligned longitudinally with the centerline of the first split ring clamp through an arc greater than degrees.

5. An attachment for inside calipers comprising a bifurcated .body portion, a first split ring clamp carried by the body portion for attaching the latter to an inside caliper, an arm having one end mounted in the bifurcation of the body meme ber for pivotal movement about an axis at right angles to the longitudinal axis of the split ring clamp, a second split ring clamp carried by the other end of the arm normally in longitudinal alignment with the first split ring clamp, an extension standard held by the second split ring clamp, the arm being swingable from a measuring position with the extension standard aligned longitudinally with the centerline of the first split ring clamp through an are greater than 30 degrees, and means for locking the arm in measuring position.

6. An attachment for inside calipers comprising a bifurcated body portion, a first split ring clamp carried by the body portion for attaching the latter to an inside caliper, an arm having one end mounted in the bifurcation of the body member for pivotal movement about an axis at right angles to the longitudinal axis of the split ring clamp, a second split ring clamp carried by the other end of the arm normally in longitudinal alignment with the first split ring clamp, an extension standard held by the second split ring clamp, the arm being swingable from a measuring position with the extension standard aligned longitudinally with the centerline of the first split ring clamp through an are greater than 30 degrees, and means for locking the arm in measuring position, said means comprising a set screw threadedly mounted in a branch of the bifurcated body portion and adapted to enter a depression in the arm.

7. An attachment for inside calipers comprising a body member, meanscarried by said body member for attaching the latter to an inside caliper, an arm mounted on the body member for pivotal movement relative thereto, an elongated straight extension standard carried by the arm, a stop on the body member and against which one side of the arm abuts in one position of the latter to limit pivotal movement thereof, means for locking said arm in abutting position, and a pivot pin mounting the arm on the body member, the longitudinal axis of said pin being perpendicular to the longitudinal axis of the extension standard and ofiset therefrom to the side adjacent the stop.

8. For use with a straight inside caliper comprised by a shank, a sleeve surrounding one end thereof and rotatable and movable longitudinally relative thereto, and an anvil projecting longitudinally from the end of said sleeve; an extension attachment comprising a body portion, means carried by the body portion for attaching the latter to the caliper sleeve, an arm connected to said body portion for pivotal movement relative thereto about an axis at right angles to the longitudinal axis of the caliper, and an extension standard held by said arm longitudinally aligned with the caliper with one end contacting the caliper anvil, the arm and extension standard being pivotable to a position in angular relation to the longitudinal axis of the caliper to reduce the overall length of the combined caliper and attachment, whereby said caliper and attachment may be inserted into otherwise inaccessible opposed grooves, recesses, or the like.

JOSHUA EARLE OAMPEN. 

